IV amantadine improves chorea in Huntington’s disease: An acute randomized, controlled study

To the Editor: A recent article reported a reduction in Huntington disease (HD) associated dyskinesia with oral amantadine.1 We performed a similar study, albeit smaller, with different results. In a double-blind, placebo-controlled crossover study approved by the University of Cape Town ethics committee, the efficacy of amantadine as an antidyskinetic agent in patients with HD was assessed. The two 6-week study arms were interspersed with a 2-week washout period. The ceiling dose of amantadine was 300 mg reached at week 3. Only subjects in good health were enrolled. Those receiving antipsychotics, antidepressants, or hydrochlorothiazides were excluded. Only eight patients (three women and five men) were enrolled (2001–2003) and randomly assigned to either arm using computer-generated numbering allocation. Medication (identical capsules containing 100 mg amantadine or placebo) was issued by the blinded treating doctor. This physician also questioned patients by phone about adverse events during the study period. The same two independent blinded observers …